package com.zzw.common.utils;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

// 图片验证码
public class ImageCode {
    static {
        System.setProperty("java.awt.headless", "true");
    }

    public static BufferedImage image(String code, int width, int height, int red, int green, int blue) {
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        g.setColor(new Color(red, green, blue));
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("Arial", Font.PLAIN, 18));
        g.setColor(new Color(134, 150, 242));
        Random random = new Random();
        for (int i = 0; i < 50; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(30);
            int yl = random.nextInt(30);
            g.drawLine(x, y, x + xl, y + yl);
        }
        for (int i = 0; i < code.length(); i++) {
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
            g.drawString(code.substring(i, i + 1), 15 * i + 3, 18);
        }
        g.dispose();
        return image;
    }

    public static BufferedImage image(String code, int red, int green, int blue) {
        return image(code, 75, 25, red, green, blue);
    }

    public static BufferedImage image(String code) {
        return image(code, 255, 255, 255);
    }

    /**
     * 对图片进行旋转
     *
     * @param src   被旋转图片
     * @param angel 旋转角度
     * @return 旋转后的图片
     */
    public static BufferedImage rotate(Image src, int angel) {
        int src_width = src.getWidth(null);
        int src_height = src.getHeight(null);
        // 计算旋转后图片的尺寸
        Rectangle rect_des = calcRotatedSize(new Rectangle(new Dimension(
                src_width, src_height)), angel);
        BufferedImage res = null;
        res = new BufferedImage(rect_des.width, rect_des.height,
                BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = res.createGraphics();
        // 进行转换
        g2.translate((rect_des.width - src_width) / 2,
                (rect_des.height - src_height) / 2);
        g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);

        g2.drawImage(src, null, null);
        return res;
    }

    /**
     * 计算旋转后的图片
     *
     * @param src   被旋转的图片
     * @param angel 旋转角度
     * @return 旋转后的图片
     */
    public static Rectangle calcRotatedSize(Rectangle src, int angel) {
        // 如果旋转的角度大于90度做相应的转换
        if (angel >= 90) {
            if (angel / 90 % 2 == 1) {
                int temp = src.height;
                src.height = src.width;
                src.width = temp;
            }
            angel = angel % 90;
        }

        double r = Math.sqrt(src.height * src.height + src.width * src.width) / 2;
        double len = 2 * Math.sin(Math.toRadians(angel) / 2) * r;
        double angel_alpha = (Math.PI - Math.toRadians(angel)) / 2;
        double angel_dalta_width = Math.atan((double) src.height / src.width);
        double angel_dalta_height = Math.atan((double) src.width / src.height);

        int len_dalta_width = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_dalta_width));
        int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_dalta_height));
        int des_width = src.width + len_dalta_width * 2;
        int des_height = src.height + len_dalta_height * 2;
        return new Rectangle(new Dimension(des_width, des_height));
    }

}
